This Section gives guidance on the performance of Test A, cold and Test B, Dry Heat. It gives reasons for the selection of an appropriate test procedure, describes the design of test equipment and provides test methods for various test parameters.The performance of components and equipments is influenced and limited by their internal temperatures which depend on the external ambient conditions and on the heat generated within the device itself. Whenever temperature gradients exist in the system formed by a device and its surroundings, a process of heat transfer will ensue.The tests cover cold and dry heat testing, with both sudden and gradual change of the temperature, and of non-heat-dissipating and heat-dissipating specimens (the latter with or without artificial cooling).The use of test chambers with and without forced air circulation is covered as appropriate. A general block diagram of the total procedure is given in Appendix A.

DR 77046

AS 60068.3.1-2003